Fluid operated latching means for inner drill assemblies



April 11, 1939. L. 1.. SNYDER FLUID OPERATED LATCHING MEANS FOR INNER D L ASSEMBLIES 2 Sheets-Sheet 1 Filed July 27', 1957 LfoA/Axeo 4. 510/052 M W 17M W w a a w 1 \Lr WV. w AX s 4 q 7 J A 1 5 M WW a 3 6 a a a April 11, 1939. 1.. L. SNYDER 2,153,815

FLUID OPERATED LATCHING MEANS FOR INNER DRILL ASSEMBLIES Filed July 27, 1957 2 sheets-sheet 2 zin/ucntcm 4:50AM 20 1,. SN V052 Patented Apr. 11, 1939 UNITED STATES PATENT, OFFICE FLUID OPERATED LATCHING MEANS FOR 1 INNER- DRILL ASSEMBLIES Leonard L. Snyder, South Gate, Calif., assignor I to Elliott Core Drilling Company,

tion of California a corpora- Application July 2'1, 1937, Serial No. 155,906

\ 14 Claims.

sembly, or a center bit assembly, in place of the core barrel during such times as the core is not to be taken. Inner drilling assemblies are especially used in drilling hard formations when the core barrel is not in use and must necessarily be locked to the outer drilling assembly in order to properly function.

The present type of means for locking inner and outer assemblies, whether the inner assembly be a core barrel or an inner drilling assembly, comprises a driving dog on the inner assembly which is adapted to engage clutch means on the outer assembly. The driving dog, as commonly used, is normally held in an outward or engaging position by means of a suitable spring and is usually adapted to be unengaged from the outer drilling assembly by a pull on the spearhead.

The present locking means employed has certain disadvantages. In the first place, when the inner assembly is dropped in the well, the driving dog, by reason of the fact that it is normally yieldably held in outward or engaging position, slidably engages the drill pipe and forcibly strikes each internally upset tool joint, thus interfering with the fall of the inner assembly. This also damages the drill pipe and the dog to same extent. Secondly, the driving dog is dependent upon springs means for holding it in engaged position. Finally, the engaging means often become stuck and is impossible to disengage.

- In view of the above disadvantages of the ordinary locking means,-it is a primary object of this invention to provide a pressure fluid operated latching means for locking inner-and outer drilling assemblies of the type-described which has none of the above disadvantages.

It is also an object of this invention to provide (oi. 255-72) e it is an object of this invention to provide a latch means or driving dog of the type described which will not hit or contact any portions of the drill pipe when the inner assembly is dropped in the well hole.

It is also an object of this invention to provide latching means which is easily disengaged.

These and other objects will be apparent from the drawingsand following description,, Referring to the drawings, which are forillustrative" purposes only,

Fig. 1 is a sectional elevation of an outer drilling assembly showing the inner drilling assembly and latching means of this invention in elevation, the inner assembly being partly broken away near the top to show a portion of its inner construction.

Fig. 2 is a fragmentary sectional elevation of the device shown in Fig. l and showing the latching means in unengaged position.

Fig. 3 is a sectional elevation similar to Fig. 2,

but showing the latching means in latched on unengaged position.

Fig. 4 is a sectional elevation of the bit head and center bit assembly of Fig. 1.

Fig. 5 is a fragmentary sectional elevation showing the latching plate in what will be termed a semi-engaged position.

Fig. 6 is a sectional plan view on line 6-6 of "Fig. 3.

Fig. '7 is a sectional plan view on'line l'| of Fig. 2.

Fig. 8 is a sectional elevation of a device showing my invention as applied to an inner core barrel.

Fig. 9 is a fragmentary sectional elevation of a modified form of latching mechanism.

Referring to the drawings, reference numeral H generally indicates an outer drilling assembly which comprises a drill collar having a lower section I2 which is externally threaded at its lower end to accommodate a bit head l3. Threaded into the upper end of section I! is a section M into which an upper sub I5 is threaded. The upper sub is adapted to be connected to a drill pipe (not shown) from which it receives rotating movement.

Mounted in the outer drilling assembly is an inner drilling assembly, generally indicated by reference numeral i6. The inner assembly com prises a center bit i'l threaded on the lower end of a driver barrel I ill. The driver barrel I8 is connected to a driver body 20 by means ,of coupling l9. The driver body'is in the form of a cylindrical tube slotted at 20' to accommodate a latch plate, to be subsequently described. Threaded into the upper end of the driver body is astop nut 2|.

Slidably mounted in the driver body is a latch bar, generally indicated by reference numeral 22, designed to actuate the latch blade. The latch bar is threaded into the lower end of a carrier body generally indicated by reference numeral 23. The carrier body terminates at its upper end in a spearhead 24 which is adapted to be engaged, as is common practice, by an overshot which may be dropped down the drill pipe on the end of 'a line. Mounted in the latch bar 22 is a latch plate 25 which is adapted to be forced outwardly by a downward action of the latch bar to engage a clutch member mounted in the outer drilling assembly and generally indicated by reference numeral 26.

In the operation of the device the latch bar and the carrier body are adapted to be forced downwardly by means of the circulating drilling fluid in order to force the latch bar outwardly into engaged position with the clutch member 26. In order to accomplish this the carrier body 23 is provided with a packing 28 which is adapted to substantially prevent circulation of the drilling fluid between the outer wall of the carrier body and the inner wall of the drill collar. The carrier body is also provided with inlet openings 29 through which the drilling fluid may enter. The openings communicate with a fluid passageway indicated by reference numeral 30, which has a restricted portion 3| therein. Although this passage has been shown in part as similar in shape to a. venturi, it is not essential to the invention that any particular shaped passageway be used, as long as there is a restricted portion at some point in the passage. The passage is provided with outlets 32 to permit escape of drilling fluid.

when drilling fluid is pumped into the well the latch bar 22 is forceddownwardly by reason of the resistance that the restricted passage 30 affords to the fluid stream. This fluid pressure operates against a compression spring 35 which serves to normally hold the latch bar in upward position. The compression spring surrounds a sleeve 36 which is designed to limit the downward movement of the latch bar. This is accomplished by limiting downward movement of the carrier body, the bottom of which abuts against the upper end of the sleeve, as shown in Fig. 3. The compression spring at its upper end abuts against the lower end of the carrier body 23 and at its lower end abuts against the stop nut 2i.

The latch bar has a cylindrical upper portion 31 which extends downwardly -to a shoulder 31 which is normally in engagement with the lower end of the stop nut 2|. Below this shoulder is a larger cylindrical portion 38 which is longitudinally slotted at 39 to accommodate the latch plate 25. Mounted in the'legs 46 and M of the latch bar are pins 42 and 43 which extend through pinslots 44 and 45 in the latch plate.

The latch plate 25 is further supported by means of a pin 41 mounted in the driver body 20 and which extends through a transverse slot 48 in the lower portion of the plate.

When the carrier body 23, and the latch bar 22 mounted therein, are forced downwardly by the pressure of the circulating fluid in the well, the latch bar is effective to force the latch plate outwardly into engagement with the clutch 26, as shown in Fig. 3. In this connection the cam surface 50 at the upper end of the slot 39 in the latch bar and the cam face 5| formed on a bridge between the legs 40 and 4| of the latch bar, engage the cam surfaces 52 and 53 on the latch plate to force the plate outwardly.

However, it should be noted that there is a delayed movement, or delayed action, in the operation of the latch plate by the latch bar. This is due to the fact that the latch bar must move downwardly a distance equal to the vertical distance between cam face 50 of the bar and face 52 of the plate before it is effective to begin forcing the plate outwardly. The advantage of this delayed action is in the fact that in going in the well, if the core barrel, or inner drill assembly should hit a tool joint and slightly compress the spring 35, bringing the latch bar down relative to the latch plate, the bar will not force the plate out. The construction thus minimizes the chance of the latch plate hitting or engaging the drill pipe when the inner assembly is dropped in the well.

By reference to Figs. 1, 3 and 6 it will be seen that the clutch member 26 comprises an annular body 54 having four depending legs 55. On the inner surface of each of the legs a shoulder 56 is provided which serves to prevent upward movement of the inner drilling assembly in the event that the plate is opposite one of the legs at the time the plate is forced outwardly. Between the upper ends of the legs are the abutment surfaces 5'! against which the shoulder 58 of the latch plate may abut to prevent upward movement of the inner assembly relative to the outer assembly. The latch plate therefore also functions as a holddown means for the inner assembly. The ordinary engaged position of the plate and clutch is shown in Figs. 3 and 6, wherein the plate extends outwardly beyond the inner edges of the legs 56.

At its lower end the driver body I9 is provided with a plug 60 which is slotted at 6| to accommodate the lower end of the latch plate 25. The plug 60 is shown secured in place by welding 62 and is provided with a central fluid passage 63.

Driver barrel I8 is connected to the lower end of the driver body 20 by coupling I9 and contains at its lower end the plug 64 which is internally threaded at 64 to accommodate the center bit ll.- These details are shown in Fig. 4, together with the construction of the bit head l3 which is threaded on the lower section l2 of the drill collar and is provided with cutting blades 65. The bit head is provided with the ordinary fluid passages 66. The bit is also provided with an annular shoulder 61, upon which the enlarged portion 68 of the center bit I! seats and is supported. The center bit I! has a fluid passage 69 which is provided with outlets in the region of the cutting teeth, but not shown.

Referring to Figs. 1, 2, 3 and 6 for the operation of the device, it can be seen that when drilling fluid is pumped down the drill pipe it is effective to force the carrier body 23'and the latch bar 22'mounted therein downwardly against the force of the compression spring 35. This movement of the latch bar forces the latch plate outwardly into driving engagement with the clutch member 26 as shown in Figs. 3 and 6.

In the event that the latch plate is directly opposite one of the legs of the clutch, it is forced outwardly as shown in Fig. 5 until the latch plate is outwardly of the inner terminus of shoulder 56. In this position the inner drilling assembly cannot rise with, respect to the outer drilling assembly, When the outer drilling assembly is rotated it will bring one of the spaces between the legs 55 of the clutch member oppo- 2,158,815 site the latch plate, which will then be further forced outwardly tothe driving or locked position, as shown in Figs. 3 and 6.

When the latch plate and clutch are in engaged position, the driving torque is transmitted from the drill collar and attached clutch member through the latch plate to the driver body 20, coupling l9, and driver barrel l8 to the center bit II. In this connection it is pointed out that part of the torque is transmitted from the latch plate through the medium of the plug 60 to the driver body. The plug also insures the return of the latch plate to the slot-in the driver body. When it is desired to disengage the latch plate from the clutch an overshot is dropped in the drill string to engage the spear-head 24. Any upward pull on the'spearhead 24 is effective to release the latch plate from the clutch member. In this connection it is pointed out that the shoulder 31' on the latch bar 22 engages the lower end of the stop nut 2| before the .pins 42 and 43 engage the upper limits of the slots 44 and 45 in the latch plate 25. With this construction when the inner drilling assembly is hoisted out of the well, there is no pressure brought to bear upon thelatch plate or pins passing therethrough. In Fig. 8 there is illustrated the adaption of the latchingassembly for use in connection with wire-line core barrels. In this flgure, reference numeral l2 generally indicates a drill collar having a bit head l3 threaded on its lower end. The

bit head is similar in .all respects to the bit head shown in Figs. 1 and 4 and the parts thereof bear corresponding reference numerals. Mounted in the.drill collar and seated in the drill head is a core barrel generally indicated by reference numerals 10 provided with a shoe I2 which seats on the annular shoulder 51. The core barrel is provided with a core catcher 14 of the usual type. The barrel I3 is provided at its upper end with a member I5 which has a relief passage 16 .therein communicating with a relief valve generally indicated by reference numeral 11 of any suitable type. Threaded on the upper end of member 15 is a plug 18 provided at its upper end with a slotted portion I9, and which is similar to the plug 58.

From this point upward the construction of the inner core barrel assembly is the same as shown in Figs. 1, 2 and 3. The operation of the device shown in Fig. 8, insofar as the latching operation is concerned, is also identical with the operation of the device shown in the other figures.

In Fig. 9 is shown a modified form of latchin plate and clutch member which is particularly designed for use in accommodating an inner drill assembly to different lengths of the member l2 of the'drill collar. In this form of the invention the latch plate is provided with a serrated edge. generally indicated by 8|, comprising the teeth 82 and the grooves 83. The latching plate 80, when forced to an outward or engaging position by the latch bar 22, as shown is adapted to engage a clutch member designated by reference numeral 84 which comprises a cylindrical member 85 threaded at 8B for attachment to the portion I4 of the drill collar. The clutch memberis provided at its lower end with an annular internal, flange 81 which is adapted to be engaged by the teeth of the latch plate. This flange is provided with four internally projecting lugs 88 which are adapted to .act in the same capacity as the legs 55 of the clutch member 26 to prevent relative rotation of the inner and outer assemblies. This is accomplished by the clutch member engaging one of the side faces of the lugs when the parts are rotated relative to each other.

In this form of the invention, when the inner assembly is dropped in the hole and becomes seated in the bit, as on shoulder 81 in Figs. 4 and 8, the circulating fluid serves to force the latch bar downwardly as in'the other forms of the invention, thereby forcing the latching plate 80 outwardly until the annular groove 81 fits into one of the grooves 83 between two of the teeth 82 on the plate. Relative rotation of the two parts is limited to the distance between adjacent lugs 88. The flange 81 and teeth 82 cooperate to prevent relative longitudinal movement of the inner and outer assemblies when the latching plate is in an engaged position.

With the construction just outlined a greater leeway is provided in the fitting of the innerassembly to'the lower section of the drill collar. Thus various sized lower sections of di'ill collar may be usedwith any given inner assembly.

I claim as my invention: I

1. In a drilling assembly for use in drilling wells where circulating drilling fluid is used, the combination of:. an outer drilling assembly; clutch means mounted in said outer drilling assembly; an inner drill assembly adapted to be supported in said outer drilling assembly; a latch -bar forming a part of the inner drill assembly; a latch plate movable by said latch bar into engagement with said clutch means for preventing relative rotative movement of said inner drill assembly; meansoperable by the circulating fluid for moving said latch bar; and means for yieldably holding said latch bar against movement.

2. In a drilling assembly for use in drilling wells where circulating drilling fluid is used, the combination of a drill pipe; a drill head on the lower end of said drill pipe; an inner annular. shoulder on the drill head; clutch means in said drill pipe; an inner drill assembly adapted to be supported by said annular shoulder; a latch bar forming a part of the inner drill assembly a latch plate movable by said latch bar into engagement with said clutch means; means operable by the circulating fluid for moving said latch bar; and means for yieldably holding said latch bar against movement.

3. For use incombination with an outer drilling assembly of the class described having a clutch member, an inner drilling assembly comprising: a driver body; a latch plate mounted in said driver body; a latch bar slidably mounted in said driver body and adapted to force said latch plate outwardly into engagement with said clutch member when said latch bar is moveddownwardly; a carrier body mounted on the upper end of said latch bar and adapted to restrict passage of drilling fluid downwardly in the drill collar; a compression spring on said bar between said driverbody and said carrier body; a center bit; and means rigidly connecting said center bit and said driver body. 4. For use in combination with an outer drill ing assembly of the class described having a clutch member, .an inner drilling assembly com- -;prising: a driver body; a latch plate mounted in said driver body; .a "latch bar slidably mounted in said driver body and adapted to force said latch plate outwardly into engagement with-said clutch member when said latch bar'ismoved having a restricted fluid passage therein; a compression spring between said driver body and said carrier body; packing means between said outer drilling assembly and said carrier body at a point below the entrance of said restricted fluid passage; a center bit; and means rigidly connecting said center bit and said driver body.

5. For use in combination with an outer drilling assembly of the class described having a rigid clutch member, an inner drilling assembly comprising: a driver body, said body having a longitudinal slot therein; a latch plate mounted in said driver body; a latch bar slidably mounted in said driver body, said bar being slotted to form legs adapted to receive said latch plate; means connecting said latch plate and the legs of said latch bar; cam faces on said latch bar engageable with said latch plate for forcing said latch plate through said slot in said driver body into engagement with said clutch member upon downward movement of said latch bar; a carrier body mounted on the upper end of said latch bar, said carrier body having a restricted fluid passage therein, a compression spring between said driver body and said carrier body;

packing means between said outer drilling assembly and said carrier body at a point below the top of said restricted fluid passage; a center bit; and means rigidly connecting said center bit and said driver body.

6. In rotary well drilling apparatus, the combination of: a drill stem; a bit head on the drill stem; an inner annular shoulder on said bit head; a tubular member seated on said shoulder; means operable by fluid pressure for locking said drill stem and said tubular member against relative movement, and means for automatically disengaging the locking means upon a substantial drop in fluid pressure.

'I. In rotary drilling apparatus, the combination of a drill stem; a bit head on the drill stem; an inner annular shoulder on said bit head; a tubular member seated on said shoulder; means operable by fluid pressure for locking said drill stem and said tubular member against relative movement, said means comprising a rigid clutch member on said drill stem, a latch plate in said tubular member, and means utilizing fluid pressure for operating said plate; and means for automatically disengaging the locking means upon a substantial drop in fluid pressure.

8. In rotary well drilling apparatus, the combination of: a drill stem; a bit head having an inner annular shoulder therein; a tubular member seated on said shoulder; a driver body mounted on said tubular member; a latch plate in said driver body; a latch bar slidably mounted in said driver body and engageable with said plate to force said plate outwardly of said driver body; rigid clutch members on said drill stem engageable by said plate; means operable by the pressure of the drilling fluid for actuating said bar; and means for yieldably holding said latch bar against movement.

9. In rotary well drilling apparatus, the combination of: a drill stem; a bit head having an inner annular shoulder therein; a tubular member seated on said shoulder; a driver body mounted on said tubular member; a latch plate in said driver body; a latch bar slidably mounted in said driver body and engageable with said plate to force said plate outwardly of said driver body; rigid clutch members on said drill stem engageable by said plate; a carrier body mounted on said latch bar, said carrier body having a restricted fluid passage therein; a compression spring between said carrier body and said driver body; and packing means between said carrier body and said drill stem at a point below the inlet of said fluid passage.

10. In a rotary well drilling apparatus, the combination of: a drill stem; a bit head on said drill stem having an inner annular shoulder; a clutch member on said drill stem; a tubular member seated on said shoulder; a driver body mounted on said tubular member, said body having a longitudinal slot therein; a latch plate mounted in 'said driver body; a latch bar slidably mounted in said driver body, said bar being slotted to form legs adapted to straddle said latch plate; means connecting said latch plate and the legs of said latch bar; cam faces on said .latch plate for forcing said latch plate through said slot in said driver body into engagement with said clutch member upon downward movement of said latch bar; a carrier body mounted on the upper end of said latch bar, said carrier body having a restricted fluid passage therein; a compression spring between'said driver'body and said carrier body; a sleeve on said latch bar above said driver body adapted to limit downward movement of said carrier body; and pack ing means between said drill stem and said carrier body at a point below the inlet of said restricted fluid passage.

11. For use in combination with an outer drilling assembly of the class described having a rigid clutch member, an inner drilling assembly comprising: a driver body, said body having a longi-- tudinal slot therein; a latch plate mounted in said driver body, said bar being slotted to form legs adapted to straddle said latch plate; means connecting said latch plate and the legs of said latch bar; cam faces on said latch bar engageable with said latch plate for forcing said latch plate through said slot in said driver body into engagement with said clutch member upon downward movement of said latch bar; a carrier body mounted on the upper end of said latch bar, said carrier body having a restricted fluid passage therein; a compression spring between said driver body and said carrier body; a sleeve member mounted on said latch bar above said driver body and having its upper end spaced from the lower end of said carrier body when said latch bar is in upward position; packing means between said outer drilling assembly and said carrier body at a point below the inlet of said restricted fluid passage; a center bit; and means rigidly connecting said center bit and said driver body.

12. In a rotary well drilling apparatus, the combination of: a drill stem; a bit head on said drill stem having an inner annular shoulder therein; a clutch member on said drill stem; a tubular member seated on said shoulder; a driver body mounted on said tubular member, said body having a longitudinal slot therein; a stop nut mounted on the top of said driver body; a latch plate mounted in said driver body; a latch bar slidably mounted in said driver body, said bar comprising an upper cylindrical rod portion terminating below the bottom of said stop nut in an enlarged portion, said enlarged portion being slotted to form legs adapted to straddle said latch plate; means connecting said latch plate and the legs of said latch bar; cam faces on said latch plate for forcing said latch plate through said slot in said driver body into engagement with said clutch member upon downward movement of said latch bar; and'a carrier body mounted on the upper end of said latch bar, said carrier body having a restricted fluid passage therein; a compression spring between said driver body and said carrier body yieldably holding said latch bar so that the upper end of said enlarged portion abuts against the lower end of said stop nut; a sleeve on said latch bar above said driver body adapted to limit downward movement of said latch bar; packing means between said drill stem and said carrier body at a point below the inlet of said restricted fluid passage.

13. In rotary drilling apparatus the combination of: a drill stem; a bit on the drill stem; an inner annular shoulder on said bit head; a tubular member seated on said shoulder; a driver body mounted on said tubular member; a latch plate in said driver body, said latch plate having a plurality of teeth formed on one edge thereof; a rigid clutch member mounted in said drill stem, said clutch member including an internal annular flange having an inwardly projecting lug formed thereon; means operable by fluid pressure for forcing said latch plate into engagement with saidannular flange of said clutch member whereby adjacent teeth of said latch plate engage said internal annular flange to prevent .relative axial movement oi! said drill stem and said driver body, said lug cooperating with said latch plate to prevent relative rotative movement of said driver body and said drill stem; and means for automatically disengaging the locking means upon a substantial drop in fluid pressure.

14. In rotary well drilling apparatus, the combination of: an outer drilling assembly adapted to accommodate an inner assembly; an inner assembly; means operable by fluid pressure for locking said outer assembly and said inner as-' sembly against relative movement; and means for automatically disengaging the locking means upon a substantial drop in fluid pressure.

LEONARD L. SNYDER. 

